The upcoming performances won’t be the only things slowed down by his ailment. Mayer’s forthcoming album, Born and Raised, “is complete as far as music recording, song selection, and in some cases mixing,” he says. However, there’s still more singing to do that will have to wait until he’s healthy—meaning it won’t be released in 2011 as he planned.

Though he doesn’t know when exactly he’ll be 100% again, John’s comfortable with the care he’s receiving. “I’m not sure how long or short a period of time it will be,” he writes. “I’ve got the best doctors in the country looking after me and I will be singing and touring again as soon as I get the all clear.”

Read his full letter after the jump:

Hi everyone,

After several months of going week to week monitoring and hoping to correct the condition, I am forced to cancel my upcoming singing engagements due to something next to my vocal cords called a granuloma.

I’m bummed to have to bow out of both the iheartradio Music Festival in Las Vegas and an appearance with Tony Bennett in Los Angeles. I know there were people depending on me to be there and I’m sorry that I can’t be on those stages.

‘Born and Raised’ is complete as far as music recording, song selection, and in some cases mixing, but because of this condition I couldn’t finish singing on several of the tracks. This means the record will be released next year instead of this fall or winter.

This is a temporary setback, though I’m not sure how long or short a period of time it will be. I’ve got the best doctors in the country looking after me and I will be singing and touring again as soon as I get the all clear. Until then I’ll be spending time writing and composing more music and kicking an empty soup can around the West Village.

I’m looking forward to seeing you again soon. Until then take good care.